Integration of MIRI into ISIM
An engineer inside the Integrated Science Instrument Module (ISIM) checks the clearances as the MIRI instrument is positioned in the ISIM using the Horizontal Integration Tool (HIT), a special balance beam that is manoeuvred using a precision overhead crane.
MIRI has to be very precisely aligned, with the periscope-like pickoff mirror (not visible) passing through a hole in the back part of the MIRI thermal shield. The required alignment accuracy for MIRI is about 50 micron, about half the width of an average human hair.
The hand on the left is gently resting against a foot of MIRI, so the engineer can sense the movement of the instrument as it is guided into place. There are typically 20-30 people involved in the integration process for MIRI.